Before and After StudyThe Established Acute Surgical Unit: A reduction in nighttime appendicectomy without increased morbidity

- An ASU provided a significant decrease in nighttime surgery.
- There was no difference in morbidity or length of stay for patients.
- No difference in complications for night time surgery.

IntroductionNighttime surgery for non-life threatening disease has been associated with poorer outcomes, but delaying surgery for acute appendicitis may also be detrimental. The aim was to assess the effect of the Acute Surgical Unit [ASU] model on nighttime surgery rates and outcomes for patients undergoing appendicectomy.MethodA retrospective review of medical records of patients having an appendicectomy. Primary outcomes were nighttime surgery rate, time from presentation to surgery, perforation rate, complication rate and length of stay.ResultsThere was a large increase in workload: Pre ASU 278, Early ASU 553 and Est. ASU 923. There was a significant decrease in nighttime surgery rates: Pre ASU 46.9%, Early ASU 30.2% and Established ASU 28.3% (Pre vs. Early p < 0.001; Pre vs. Est. p < 0.001; Early vs. Est p = 0.004). When comparing the Pre ASU and Established ASU groups there was an increase in mean time from presentation to surgery (Pre 14.43 Hrs, Est. 18.65 Hrs; p = 0.001), an increase in perforation rate that was not significant (Pre 9.8%, Est. 14.2%; p = 0.05) and similar complication rates (Pre 8.66%, Est. 7.04%; p = 0.37). There was a significant decrease in length of stay between the Early and Established ASU groups (Pre 3.1 D, Est. 2.8D, p = 0.01). At our institution there was no statistically significant increase in complications for patients undergoing nighttime appendicectomy (Night 10.0%, Day 8.2%; p = 0.16).ConclusionThere was a significant decrease in nighttime surgery, without any difference in morbidity or length of stay for patients treated within the Established ASU (compared to Pre ASU group).Level of evidenceIIb.